According to the principle of blockhain, the more transaction that is verified and confirmed, the more secure it will be.
We all know that Bicoin starts several ago and undeniably the most secure platform up to date as long as the principle is concerned but Ethereum has more capabilities than bitcoin and we all know that most of the coins that are emerging is an ERC20 type of coin which uses Ethereum platform.
In your mind, which platform will have more transactions and therefore secure in the future.
Keep in mind that Ethereum starts 3 years ago while Bitcoin starts 9 years ago. Also consider the fact that Ethereum can handle more transaction per second than bitcoin.
I choose both, Bitcoin and Ethereum because those two are great crypto, easily to use, safe and secured to invest and those are great future. In handling the transaction, Ethereum is Faster and lower transaction fee compare to bitcoin and Ethereum it is mostly used in investing from the ICO.